NNB
My understanding is that while Cessna put a time limit on the airframe, it was in the context that they were not prepared to provide a maintenance schedule for the aircraft beyond that time.
It was CASA that made it a mandatory grounding at that time but subject to there being no acceptable maintenance schedule being developed. Now, I think that there are one or two maintenance companies that have been looking at a maintenance programme for the aircraft to enable them to continue in service.